Method for producing earth boreholes

ABSTRACT

In a method for producing and widening ground bores or for the destructive replacement of buried lines with the aid of a tool arranged at the end of a rod driven by a boring device, the rod is built up from individual sections which are to be connected to one another in a machine excavation (staring excavation). In order to allow the use even of rod sections whose length is equal or almost equal to the diameter of the machine excavation, the boring device, prior to the introduction of a new rod section, is displaced, for example inclined, in such a manner that the rod section can be slid into the boring device, for example from outside the excavation, without interference from the rear end, projecting into the machine excavation, of a rod section which has already been introduced into the ground. As soon as the rod section has been slid in, the boring device together with the rod section is moved into a position in which it is aligned with the boring direction or the rod part which is already in the ground.

[0001] The invention relates to a method for producing and wideningground bores or for the destructive replacement of lines which have beenlaid in the ground, and invokes the priorities of German patentapplications 101 34 036.2 and 101 59 712.6-24, to the content of whichreference is made.

[0002] Methods of this type generally use a boring device which issuitable for horizontal boring and has a rod, at the free end of which atool is suitable for boring and/or widening in the ground or fordestroying an old pipe which has been laid in the ground. The rodcomprises individual sections which are screwed together or are fittedand screwed to the rear end of the rod part which is already in theground. However, this fitting and screwing operation encountersdifficulties, since the boring device must be located at the level ofthe ground bore or of the old pipe and accordingly is usually arrangedin a starting excavation, i.e. in an excavation which has previouslybeen dug or in an existing manhole of a sewerage system.

[0003] The total length of the rod section and of the boring device maycorrespond to at most the diameter of the manhole or of the manholeopening, so that there is still space behind the boring device for a rodsection to be pushed axially into the boring device in order for a newrod section to be connected to the rod part which is already in theground, after which operation of the boring device recommences in orderto introduce the rod section which has been fitted. Given a distance ofup to 60 m between the manholes and a standard manhole diameter of 100to 120 cm, and at most 160 cm, this means that introducing a rod sectionover the entire distance entails a considerable outlay on time.

[0004] Moreover, on account of the shortness of the rod sections, alarge number of—for example 60 or 70—expensive socket or screwconnections which are susceptible to faults are required. An additionalfactor is that with pneumatically driven boring devices there arestarting difficulties if the length of hose running from a compressor tothe boring device exceeds a certain level.

[0005] The abovementioned problems occur both if a new ground bore isproduced between manholes and a new pipeline is introduced and if an oldpipeline which is destroyed by a cutting tool on the rod in order for anew pipeline subsequently to be introduced is present between themanholes.

[0006] In the case of boring with a boring device arranged in anexcavation which has been dug, the same difficulties arise if theexcavation is of approximately the same width as a standard manhole;they can be eliminated or alleviated if the clear width is(considerably) larger. However, this requires a correspondinglyincreased amount of earth to be excavated and therefore entailsincreased costs. Moreover, it presents problems on account of the needto temporarily store or transport away the soil which has beenexcavated.

[0007] The journal “s+t46 (1992)11”, pages 10, 12, 14, has also alreadydisclosed a method for the trench-free laying of supply lines in whichfirst of all two excavations, i.e. a starting excavation and a targetexcavation, are dug. Then, a boring device which is located above theground and works obliquely creates an inclined bore with respect to thestarting excavation and then a substantially horizontal bore leading tothe target excavation. Then, the boring rod is provided in the targetexcavation with a widening head which works in the opposite directionand is finally pulled back until it reaches the starting excavation.

[0008] However, it is often not acceptable or highly complex to producean auxiliary bore, requiring subsequent closure of the auxiliary boreand restoration of the hole wall and of the surrounding surface finish(road surfacing, forecourt plants, etc.).

[0009] Therefore, the invention is based on the problem of avoiding thedrawbacks which result from the limited length of the rod sections orthe need to dig out an excavation with a diameter which is suitable forlonger rod sections or to produce and then eliminate an auxiliary bore.

[0010] To avoid these drawbacks, the invention proposes a method inwhich the component which receives the rod sections (i.e. the rodreceiving part) or the entire boring device is first of all moved into aspatial position which allows the rod sections to be introduced into therod receiving part without being impeded by the rear end, projectinginto the machine excavation, of a rod section which has already beenintroduced into the ground. As soon as this has taken place, the rodreceiving part or the boring device is moved back into the boringposition, i.e. flush with the bore or that part of the rod which isalready in the ground, where it is connected to the last rod section ofthe rod part which is already in the ground.

[0011] In the present context, the term rod receiving part is to beunderstood as meaning that part of a boring device which on one side isconnected to the boring drive and on the other side receives the rearend of a rod section before this rod section is connected to theprevious rod section. A rod receiving part of this type, in the form ofa plug coupling, is described in German patent 197 25 628 and thecorresponding U.S. Pat. No. 6,267,187.

[0012] To introduce a rod section, it is sufficient for the receivingpart for the rod section, for example a coupling on the rotary drive forthe rod, to be moved out of its boring position, for example to bedisplaced upward.

[0013] The change in position of a standard boring device can also beeffected by pivoting between the boring position and the receivingposition. Another possible option consists in moving the receiving partfor the rod sections or the boring device between the two positions withthe aid of a raising carriage or a type of lifting platform, whichenable the rod sections to be introduced into the device above theboring level, for example at ground level.

[0014] In the case of pivoting, it is possible to use a boring devicewhich is provided with at least one pivot bearing at the front or therear, as seen in the boring direction. A device of this type maycomprise a basic frame and a mounting which is arranged pivotablythereon and includes the actual boring device. In this case, a pivotdrive, for example a hydraulic or pneumatic cylinder, is located betweenthe basic frame and the mounting. Furthermore, the basic frame and themounting may be provided with a locking mechanism which secures theboring device so as to prevent undesired movements during boring.

[0015] However, the basic frame may also serve as a lifting platform orbe arranged on a lifting platform, by means of which the device is movedout of the boring position of variable height to the ground level, inorder for a new rod section to be pushed in at that level or—in a targetexcavation—to be removed.

[0016] Use of the apparatus according to the invention results in theadvantage that the pipe sections, in order to be pushed into the boringdevice or to be removed, do not require any additional space in anexisting manhole or in a starting excavation which has been dug out;therefore, they may have a length which corresponds to the hole diameteror to the length of the boring device. On the other hand, when theapparatus according to the invention is used, there is no need for thedimension of the machine excavation in the horizontal direction to beany greater than approximately the length of the boring device.

[0017] The invention is explained in more detail below with reference totwo exemplary embodiments. In the drawing:

[0018]FIG. 1 shows a boring device according to the invention in itsboring position in an existing manhole,

[0019]FIG. 2 shows the device shown in FIG. 1 in its receiving position,

[0020]FIG. 3 shows a boring device arranged pivotably on a raisingcarriage in three different height positions,

[0021]FIG. 4 shows a boring device on a lifting platform in its boringposition, and

[0022]FIG. 5 shows a boring device shown in FIG. 3 in its receivingposition above ground, and

[0023]FIG. 6 shows a boring device, the rotary drive of which isvertically displaceable.

[0024] In a standard manhole 1 (machine excavation/target excavation)with a narrowed opening 2, there is a platform 3 on supports 4 bearing aboring device 5. The boring device comprises a basic frame 6, which isconnected, via a pivot bearing 7, to a mounting 8, on which an advancingdrive 9 and a rotary drive 10 are positioned. The advancing drive mayalso be arranged on the basic frame 6. The rotary drive 10 has a hollowshaft (not shown) which is such that it is able to receive a pipesection 11, the front end 12 of which can be screwed to the last rodsection 13 of that part of the rod which is already in the ground. Toallow this to occur, a clamping device 14 for holding the rod section 13in place is located on the mounting 8. Force is transmitted between thehollow shaft and the rod section 11 by means of a positive lock orfrictional lock.

[0025] As soon as the rod section 11 has been screwed to the rod section13, the advancing drive 9 forces the rod 11, 13 into the ground untilthe rear end of the rod section 11 is in the situation of the rodsection 13 and the mounting 8 has been “emptied”. Then, the mounting 8is pivoted out of the boring position illustrated in FIG. 1 into thereceiving position illustrated in FIG. 2. This is preferably effectedwith the aid of a hydraulic cylinder 15 extending between the basicframe of the mounting until the mounting 8 has adopted a position inwhich the extension of the hollow shaft axis 16 extends within theopening 2 of the manhole 1. In this position, it is readily possible fora rod section 11 with a length of approximately the whole diameter to beintroduced into the hollow shaft until it has reached the positionillustrated in FIG. 2. Then, the mounting together with the new rodsection can readily be pivoted back out of this position into the boringposition illustrated in FIG. 1.

[0026] In the exemplary embodiment shown in FIG. 3, the boring device 5is arranged on a raising carriage 17. The raising carriage can bedisplaced in a framework 18 arranged in the manhole 1 and is connectedto a pivoting drive (not shown), for example a hydraulic cylinder, whichallows the boring device to be arranged in an inclined position. In thisway, it is possible to move a boring device through the narrowed holeopening 2 in the inclined position and thereby to move it into anabove-ground receiving position, even if its length is greater than theclear width of the hole opening 2. As soon as the boring device 5 hasreached its upper position in FIG. 3, it is pivoted back into ahorizontal position in order to receive a rod section.

[0027] The boring device 5 shown in FIG. 4 and 5, which is used in adug-out machine or starting excavation 19, is situated on a liftingplatform 20 which can be displaced, between supports 21, between theboring position (FIG. 4) and the receiving position above ground.

[0028] In the case of the boring device illustrated in FIG. 6, therotary drive 10 is connected to a raising drive 22, which allows therotary drive together with its receiving part 23 for the rear end of arod section 11 to be displaced out of the boring position, in which itis aligned with the rod section 13 which is already in the ground,upwards into the position illustrated. In this position, it is possiblefor rod section 11 which is longer than the distance between the rotarydrive 10 and the rear end of the rod section 14 which is already in theground to be introduced into the receiving part 23.

1. A method for producing and widening ground bores or for thedestructive replacement of buried pipelines with the aid of a boringdevice which is arranged in a starting excavation and has a boring rodcomprising a plurality of sections, characterized in that not all theboring device, but rather the rotary drive for the advancement or atleast part thereof which includes the receiving part for the rodsections, is moved out of its boring position in the starting excavationin order for a rod section to be introduced or removed, and the rotarydrive for the advancement or at least a part thereof which includes thereceiving part for the rod sections is moved back into the boringposition after a rod section has been introduced or removed.
 2. Themethod as claimed in claim 1, characterized in that the receiving partof the boring device for a rod section is moved upward.
 3. The method asclaimed in claim 1 or 2, characterized in that the rod receiving part ofthe boring device is moved out of it boring position.
 4. The method asclaimed in claim 1, characterized in that for introduction or removal ofa rod section in the rod receiving part, the boring device is moved outof its boring position in the starting excavation into a position whichallows a pipe section to be introduced into the rod receiving part fromoutside the starting excavation.
 5. The method as claimed in claim 1,characterized in that the boring device is pivoted out of its boringposition into a receiving position in the starting excavation.
 6. Themethod as claimed in claim 5, characterized in that the boring device ismoved out of its boring position in the starting excavation into areceiving or removal position outside the starting excavation, into aposition above ground.
 7. The method as claimed in claim 1 or 2,characterized in that the rod receiving part of the boring device israised.
 8. The method as claimed in one of claim 1 to 6, characterizedin that the boring device is pivoted in the starting excavation into aninclined position about a rotation point located at the front or therear.
 9. The use of a boring device having a receiving part (23) for rodsections (11) and a pivot bearing (7) arranged at the front or rear inthe boring direction for the method as claimed on one of claims 1 to 5in claim
 1. 10. The use of a boring device, the receiving part (23) forrod sections (11) of which is provided with a raising drive (22), forthe method as claimed in one of claims 1, 2 and 7 claim
 1. 11. The useof a boring device, arranged on a raising carriage (17) or a liftingplatform (20) for the method as claimed in claim 6.